The invention relates to a method of controlling and/or regulating an automated transmission of a vehicle, in particular a motor vehicle, with a gear-shift strategy that is determined on the basis of at least one shift characteristic which may be represented graphically as a curve.
The known state of automotive technology includes in particular automated transmissions that provide the possibility of automating the power train of a vehicle.
Under a known method used in the power plants of state-of-the-art motor vehicles, a suitable gear-shift strategy is carried out on the basis of a shift characteristic. According to the known method, the gear-shift strategy normally follows a shift characteristic that is designed so that the engine delivers a strong torque already with a slight actuation of the accelerator pedal in order to give the driver the impression of a sport-oriented vehicle response. As a consequence, when the driver subsequently depresses the accelerator pedal more strongly, the engine torque can only be increased by a small additional amount.
Thus, when the driver indicates a desire to accelerate the vehicle, it is possible with the prior-art-method that the transmission shifts too early into a higher gear, or in case of a low engine torque and an indication that a smaller amount of acceleration is requested, a lower than required gear-ratio may be maintained too long. Overall, this behavior of the transmission has an unfavorable effect on fuel consumption in a vehicle where the prior-art method is used.
Furthermore, up-shifts under less than full engine power with small amounts of pedal depression can lead to an undesirable oscillating shift behavior of alternating up- and down shifts. Under the gear-shift strategy of the prior-art method it is possible, e.g., that under full engine torque with an intermediate amount of pedal depression, the transmission is kept in a low gear for too long, or it is possible that a downshift fails to occur with a kick-down depression of the accelerator pedal and a high engine torque. Accordingly, it is possible that a tip-in (slight, rapid actuation of the gas pedal) at a low engine rpm-rate will cause an unwanted downshift due to the aggressive engine behavior, even though the accelerator pedal has been depressed only slightly.
As a result, the gear-shift strategy in the state-of-the-art methods is unpredictable for the driver. Overall, this lowers the comfort level of the driver in a vehicle where the state-of-the-art method is used to control the transmission.